title: Rapid biotransformation of arsenate into oxo-arsenosugars by a freshwater unicellular green alga, Chlamydomonas reinhardtii.
abstract: We examined the short-term metabolic processes of arsenate for 24 h in a freshwater unicellular green alga, Chlamydomonas reinhardtii wild-type strain CC-125. The arsenic species in the algal extracts were identified by high-performance liquid chromatography/inductively coupled plasma mass spectrometry after water extraction using a sonicator. Speciation analyses of arsenic showed that the levels of arsenite, arsenate, and methylarsonic acid in the cells rapidly increased for 30 min to 1 h, and those of dimethylarsinic acid and oxo-arsenosugar-glycerol also tended to increase continuously for 24 h, while that of oxo-arsenosugar-phosphate was quite low and fluctuated throughout the experiment. These results indicate that this alga can rapidly biotransform arsenate into oxo-arsenosugar-glycerol for at least 10 min and then oxo-arsenosugar-phosphate through both reduction of incorporated arsenate to arsenite and methylation of arsenite and/or arsenate retained in the cells to dimethylarsinic acid via methylarsonic acid as an possible intermediate.
authors.affiliation: School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan. s037104@toyaku.ac.jp
authors.forename: Shinichi
authors.initials: S
authors.lastname: Miyashita
authors.forename: Shoko
authors.initials: S
authors.lastname: Fujiwara
authors.forename: Mikio
authors.initials: M
authors.lastname: Tsuzuki
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Kaise
mesh_terms: D001149:Arsenates / Q000378:metabolism*; D001151:Arsenic / Q000378:metabolism*; D001152:Arsenicals / Q000378:metabolism; D018053:Arsenites / Q000378:metabolism; D001711:Biotransformation; D002101:Cacodylic Acid / Q000378:metabolism; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005618:Fresh Water; D013058:Mass Spectrometry; D008745:Methylation; D009005:Monosaccharides / Q000378:metabolism*; D013010:Sonication
chemical_list: D001149:Arsenates; D001152:Arsenicals; D018053:Arsenites; D009005:Monosaccharides; C449161:arsenosugar; D002101:Cacodylic Acid; C020300:monomethylarsonic acid; C015001:arsenite; D001151:Arsenic; C025657:arsenic acid